THE MOUNT DESERT REGION 69 



PROTOZOA 



RHIZOPODA 

 Order FORAMINIFERA 



From the coast of New England north of Cape Cod there 

 are recorded in the literature 23 species of Foraminif era from 

 depths of 50 fathoms or less. Our survey material contains 

 at present at least 38 species. Fifteen of these are entirely 

 new to the New England region, 10 are recorded from other 

 portions of the region, either south of Cape Cod, or (one 

 species) from depths between 50 and 100 fathoms. The 

 remaining 9 species were already recorded from shallow 

 water in northern New England. Fourteen of the 23 species 

 first mentioned have not yet been taken. 



Whiteaves reports 63 species from eastern Canada. Of 

 these we have taken about 16. It is difficult, however, to 

 determine exactly to what some of Whiteaves ' names refer. 



Haplopliragmoides scitulus, previously recorded only from 

 south of Nantucket in 78 to 129 fathoms, we have in French- 

 mans Bay at a depth of 40 fathoms. 



Several of our forms, such as Discorbis ohtnsa and Crithio- 

 nina pisum, exhibit only small and juvenile forms. These 

 hardly show enough of the true character of the species to 

 enable them to be recognized. Some of these species are 

 probably not fully developed anywhere in the region. An 

 observation to be detailed below leads me to feel that these 

 variations in development are not dependent on the ordinary 

 factors of geographic variation, temperature, depth, salinity, 

 etc., but are more dependent on the chance that an individual 

 does or does not find itself in a position favorable to maximum 

 development by reason of shelter and food supply. 



The observation mentioned above concerns Haploplirag- 

 moides canariensis, Quinqueloculina semimda, and Q. fusca. 

 These species have been taken free in sand or sandy mud. 

 The specimens are uniformly small, though exhibiting per- 

 fectly the specific characters. 



